To enable the dental professional to place composite fillings, matrices are used. A matrix is a device which wraps around the tooth and acts as a mould to contain composite resins before they are cured. Matrices are generally formed of plastic or stainless steel and are either circumferential or sectional. Sectional matrices fit only in one proximal area of the tooth while circumferential matrix bands fit around the entire circumference of the tooth. Matrices are secured in place by the use of wedges and/or clamps. The prior art wedges are generally made of wood or plastic and are placed between the matrix and an adjacent tooth. Wedges are used to hold the matrix against the tooth being filled and to temporarily separate the tooth being filled and the adjacent tooth.
Preparing for a class II filling poses a major risk of damaging the adjacent tooth. Various studies have concluded that adjacent teeth are damaged during such preparation in anywhere from 66-90% of all cases. Metal shields have been employed to provide a barrier between adjacent teeth during preparation for the filling. However, the shield on many protection devices loosens when the approximal contact point is cut away, thus increasing the risk of accidental aspiration of the shield. In addition, shields in prior art devices must be removed and discarded upon completion of the preparation phase and replaced with a traditional dental wedge during the restoration phase.